USS R-12 (SS-89) was a R1-class World War II era submarine.
Only two United States submarines were lost in the Atlantic during World War II, both in 1943: R-12 and USS Dorado (SS-248).
On June 12, 1943, R-12, captained by Lieutenant Commander Edward E. Shelby, got underway from Key West, Florida to conduct a torpedo practice approach. As she completed preparations to dive, her forward battery compartment began to flood. The sea began rushing in and R-12 sank within fifteen seconds in 600 feet of water at the geographic position 24° 12′ 30″ N, 81° 38′ 30″ W. Two officers and three enlisted men, who were on the bridge, were the only survivors. The men lost included four U. S. Navy officers, thirty-six U. S. Navy enlisted men, and two Brazilian observers. It was the opinion of a Court of Inquiry that the exact cause for the loss of R-12 was unknown, but was probably due to rapid flooding of the forward part of the ship through a torpedo tube. 1
A list of the personnel lost with R-12 is maintained at On Eternal Patrol.
On May 24, 2011, the RV Tiburon Team announced it had discovered the wreck of the USS R-12 off the Florida Keys.
1. Roscoe, Theodore, United States Submarine Operations in World War II, p. 248.